40g Large Raisins soaked overnight in 2 Tbsp of Rum or orange juice then drained

1 x 20.5cm spring clip tin greased and a baking sheet

1) Preheat the oven to 160 c . Crush the biscuits in a food processor then mix them with the butter, press onto the base and halfway up the sides of the prepared tin. Bake for 5 mins then cool.

2) Using an electric mixer on low speed . beat the cream cheese with the flour , sugar , vanilla , eggs , egg yolk and half of the soured cream until thoroughly combined. Don’t let the mixture become frothy as this will spoil the creamy , even texture of the cheesecake. Stir in the raisins , reserving a few for decoration , if you like.

3) Pour the mixture into the tin on top of the biscuit base. Set the tin on the baking sheet and bake for 40 mins. Stir the remaining soured cream , then carefully pour it over the top of the cheesecake, the top will still be fragile so if you need to spread the soured cream do this gently. Bake for a further 15 mins or until the cheesecake is set but still slightly wobbly in the center.

4) Remove from the oven and run a round bladed knife around the inside of the tin to loosen the cheesecake. Leave to cool in the tin . then cover and chill overnight before unmoulding for serving and scattering with the reserved raisins . if you like .